US EPA

1575613 

Journal Article 

Interactions between Bacillus cereus strain L7 and Anabaena flos-aquae during cyanobacterial blooms 

Zhang, H; Pan, W; Chen, B; Zhan, S 

2012 

Yes 

Fundamental and Applied Limnology
ISSN: 1863-9135
EISSN: 2363-7110 

181 

2 

103-112 

10.1127/1863-9135/2012/0326 

WOS:000308743600002 

Growth of cyanobacteria can easily cause cyanobacterial
blooms. Cyanobacteria-algicidal bacteria interactions are a major regulatory factor of
cyanobacteria growth during the entire cyanobacterial bloom period. Interactions between
algicidal bacteria (Bacillus cereus strain L7) and cyanobacteria (Anabaena flos-aquae) during
cyanobacterial blooms were investigated in different axenic microcosms. Changes in the Bacillus
cereus strain L7 and Anabaena flos-aquae cell concentrations, malondialdehyde concentrations, and
concentrations of NH4+-N and NO3--N in microcosms were evaluated. Lower concentrations of
Bacillus cereus strain L7 stimulated growth of Anabaena flos-aquae, while higher concentrations
inhibited cyanobacterial growth. Bacillus cereus strain L7 growth was inhibited by extracellular
metabolites of Anabaena flos-aquae but promoted by intracellular metabolites of the
cyanobacteria. Bacillus cereus strain L7 may promote transformation of nitrate nitrogen into
ammonium nitrogen that could be directly and easily utilized by Anabaena flos-aquae. However,
higher Bacillus cereus strain L7 concentration (1.75x10(8) CFUs/mL) increased malondialdehyde
concentration, suggesting it could damage cyanobateria via peroxidation. Thus, we concluded that
cyanobacteria and algicidal bacteria have both mutualistic and antagonistic effects on each
other. We also propose a model to illustrate the interactions between both populations during the
bloom. This study allows us to better understand the interactions between algicidal bacteria and
cyanobacteria during a cyanobacterial bloom and the role of algicidal bacteria during the
development and declining stages of the bloom. In addition, this study will support the direct
utilization of algicidal bacteria to control a cyanobacterial bloom. 

Algicidal bacteria; Bacillus cereus strain L7; Anabaena flos-aquae; Cyanobacterial blooms; Cyanobacteria-bacteria interactions